31P and 1H spectra have been obtained on intact isolated and superfused toad retinae. Up to eight retinae are studied in a commercial probe and a single retina is studied in a purpose-built small-sample spectroscopy probe. Adequacy of tissue maintenance conditions has been demonstrated. Differences in phosphorus metabolite concentrations have been observed under conditions of light and dark adaptation. Cyclic GMP has been demonstrated in the 31P NMR spectrum of retina.The Pa/Pi ratio increases and [La] decreases in high calcium solution, a useful finding since calcium is thought to be involved in light adaptation.When the Na/K pump is blocked with ouabain in low calcium, both Pa/Pi and lactate decrease, suggesting differing functional roles for anaerobic and aerobic glycolysis.